A prevalent practice in the taking of check-bites for use in adjusting a dental articulator involves fastening of clutches to the respective upper and lower arches of the patient's teeth or the patient's alveolar ridges. The clutches are secured to center bearing plates and are placed in the space between the tongue and the palate and are separated by a bearing stud. In order to get a reading of the jaw movements, the patient must hold his jaw in each position while fast-setting non-expandable stone is injected between the center bearing plates of the clutches. After the stone sets to fix the upper and lower clutches, the clutches are removed from the patient's mouth and placed between the models on the articulator for setting the articulator for the particular excursion. The stone is then removed and the center bearing plates cleaned for attaching the clutches in the patient's mouth to repeat the foregoing operation for the next excursion. As aforesaid, three check-bites are usually taken for adjusting the articulator i.e. one with the jaw moved to the right, one with the jaw moved to the left, and one with the jaw moved forward. To assist the patient in holding the jaw in the respective lateral check-bite positions while the injection stone is setting, the upper bearing plate will be formed with shallow depressions corresponding to the respective check-bite positions in which the rounded upper end of the bearing stud is engaged.
This method of fixing the clutches and center bearing plates by the use of stone has a number of disadvantages, namely, the mixing of the stone and the waiting for it to set in the mouth is time-consuming, the injecting of the stone between the center bearing plates without the patient moving the jaw is awkward, the patient has to hold perfectly still while the stone is setting and this may take several minutes for each check-bite, and the check-bite clutches and center bearing plates and mixing equipment have to be cleaned after each use. Furthermore, there is the added time and expense of forming the aforesaid shallow depressions in the upper bearing plate for each patient, and the added expense of replacement of upper bearing plates when the shallow depressions made for prior patients begin to interfere with the jaw excursions of a new patient.